Abstract
Purpose :
Age-related macular degeneration (AMD) is the progressive degeneration of the retinal pigment epithelium (RPE) retina among elderly individuals. Steady exposure to light is thought as an important factor in disease progression.
Light-induced retinal degeneration models have been established in zebrafish, but little is known about the change of RPEs under light-induced damage. Furthermore, the different effect of the white light and blue light on RPE is not also elucidated especially in the adult pigmented zebrafish.
The present study aimed to investigate the changes in the RPE layer against white light and blue light irradiation in adult pigmented zebrafish.
Methods :
Wildtype adult zebrafish (6 months – 1 year old) were maintained in water tanks under dark adaptation. Then they were irradiated by white LED (10,000 Lux) and blue light LED (10,000 Lux, 450 nm) for 48 hours and 96 hours. Outer nuclear layer (ONL) thickness was evaluated through hematoxylin & eosin staining. The thickness of RPE, cone, and rod cell layers were also measured in the immunostained image using zpr-2, -1, and -3 antibodies. To compare the thickness of the interested layer after 48 hours and 96 hours from the baseline timepoint, one-way ANOVA with post-hoc Dunnett test was done.
Results :
Under white-light irradiation, the thickness of the ONL layer and cone and rod cell layers started to be reduced significantly after 48 hours (P=0.002, P=0.001, P=0.002, respectively). However, the thickness of the RPE layer was not reduced until 96 hours by white light (P=0.17).
The blue-light irradiation induced the thinning of the RPE layer and rod cell layer after 96 hours (P=0.04, P=0.03, respectively). On the other hand, the thicknesses of ONL and cone cell layers were not changed until 96 hours (P=0.06, 0.11, respectively).
Conclusions :
Exposure to blue light-induced the RPE layer's thinning in the adult pigmented zebrafish, while white light did not. This result might be helpful in establishing a zebrafish model related to age-related retinal diseases like AMD.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.